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采用真空熔炼法制备三种不同相态的Mg-xLi-1Al三元合金,并使用光学显微镜、X射线衍射分析及动态力学分析仪研究其显微组织及阻尼性能。结果表明:由于锂含量的增加,合金的相结构发生转变且出现新的阻尼机制,其中BCC结构的出现使阻尼性能显著提高,同时弹性模量的减小也使临界应变振幅值降低。两相共存状态的合金随温度变化表现出较高的阻尼现象,并在低温与高温区均出现两个较为明显的峰值,其中低温区的P1峰是位错阻尼峰,高温区的P2峰是晶界阻尼峰。
Three different phases of Mg-xLi-1Al ternary alloy were prepared by vacuum melting method and the microstructure and damping properties were studied by optical microscope, X-ray diffraction analysis and dynamic mechanical analyzer. The results show that due to the increase of lithium content, the phase structure of the alloy changes and a new damping mechanism appears. The appearance of BCC structure enhances the damping capacity remarkably and decreases the critical strain amplitude. The alloy with two phases coexist shows a higher damping phenomenon with temperature, and two obvious peaks appear in the low temperature and the high temperature, in which the P1 peak in the low temperature region is the dislocation damping peak and the P2 peak in the high temperature region is Grain boundary damping peak.